osgEarth 2.1.1

/home/cube/sources/osgearth/src/osgEarthDrivers/osg/OSGTileSource.cpp

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00001 /* -*-c++-*- */
00002 /* osgEarth - Dynamic map generation toolkit for OpenSceneGraph
00003  * Copyright 2008-2010 Pelican Mapping
00004  * http://osgearth.org
00005  *
00006  * osgEarth is free software; you can redistribute it and/or modify
00007  * it under the terms of the GNU Lesser General Public License as published by
00008  * the Free Software Foundation; either version 2 of the License, or
00009  * (at your option) any later version.
00010  *
00011  * This program is distributed in the hope that it will be useful,
00012  * but WITHOUT ANY WARRANTY; without even the implied warranty of
00013  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
00014  * GNU Lesser General Public License for more details.
00015  *
00016  * You should have received a copy of the GNU Lesser General Public License
00017  * along with this program.  If not, see <http://www.gnu.org/licenses/>
00018  */
00019 #include "OSGOptions"
00020 
00021 #include <osgEarth/HTTPClient>
00022 #include <osgEarth/FileUtils>
00023 #include <osgEarth/ImageUtils>
00024 #include <osgDB/FileNameUtils>
00025 
00026 #include <cstring>
00027 
00028 #define LC "[OSG Driver] "
00029 
00030 #define LOG2(X) (::log((double)(X))/::log(2.0))
00031 
00032 using namespace osgEarth;
00033 using namespace osgEarth::Drivers;
00034 
00035 struct CopyAndSetAlpha
00036 {
00037     bool operator()( const osg::Vec4& in, osg::Vec4& out ) {
00038         out = in;
00039         out.a() = 0.3333*(in.r() + in.g() + in.b());
00040         return true;
00041     }
00042 };
00043 
00044 static
00045 osg::Image* makeRGBAandComputeAlpha(osg::Image* image)
00046 {
00047     osg::Image* result = new osg::Image();
00048     result->allocateImage( image->s(), image->t(), image->r(), GL_RGBA, GL_UNSIGNED_BYTE );
00049     result->setInternalTextureFormat( GL_RGBA8 );
00050     ImageUtils::PixelVisitor<CopyAndSetAlpha>().accept( image, result );
00051     return result;
00052 }
00053 
00054 class OSGTileSource : public TileSource
00055 {
00056 public:
00057     OSGTileSource( const TileSourceOptions& options ) :
00058       TileSource( options ),      
00059       _maxDataLevel( 21 ),
00060       _options( options )
00061     {
00062         //nop
00063     }
00064 
00065     void initialize( const std::string& referenceURI, const Profile* overrideProfile)
00066     {
00067         if ( !overrideProfile )
00068         {
00069             OE_WARN << LC << "An explicit profile definition is required by the OSG driver." << std::endl;
00070             return;
00071         }
00072 
00073         setProfile( overrideProfile );
00074 
00075         osg::ref_ptr<osg::Image> image;
00076 
00077         URI url = _options.url().value();
00078         if ( !url.empty() )
00079         {
00080             url = URI( url.full(), referenceURI ); // obselete?
00081             HTTPClient::ResultCode code = HTTPClient::readImageFile( url.full(), image );
00082             if ( code != HTTPClient::RESULT_OK )
00083             {
00084                 OE_WARN << LC << "Failed to load data from \"" << url.full() << "\", because: " << 
00085                     HTTPClient::getResultCodeString(code) << std::endl;
00086             }
00087         }
00088 
00089         if ( !image.valid() )
00090             OE_WARN << LC << "Faild to load data from \"" << url.full() << "\"" << std::endl;
00091 
00092         // calculate and store the maximum LOD for which to return data
00093         if ( image.valid() )
00094         {
00095             int minSpan = osg::minimum( image->s(), image->t() );
00096             int tileSize = _options.tileSize().value();
00097             _maxDataLevel = (int)LOG2((minSpan/tileSize)+1);
00098             //OE_NOTICE << "[osgEarth::OSG driver] minSpan=" << minSpan << ", _tileSize=" << tileSize << ", maxDataLevel = " << _maxDataLevel << std::endl;
00099 
00100             
00101             getDataExtents().push_back( DataExtent(overrideProfile->getExtent(), 0, _maxDataLevel) );
00102 
00103             bool computeAlpha =
00104                 (_options.convertLuminanceToRGBA() == true && image->getPixelFormat() == GL_LUMINANCE) ||
00105                 (_options.addAlpha() == true && !ImageUtils::hasAlphaChannel( image.get() ) );
00106 
00107             if ( computeAlpha )
00108             {
00109                 image = makeRGBAandComputeAlpha( image.get() );
00110             }
00111             else if ( ImageUtils::hasAlphaChannel( image.get() ))
00112             {
00113                 image = ImageUtils::convertToRGBA8( image.get() );
00114             }
00115             else
00116             {
00117                 image = ImageUtils::convertToRGB8( image.get() );
00118             }
00119 
00120             _image = GeoImage( image.get(), getProfile()->getExtent() );
00121         }
00122 
00123         _extension = osgDB::getFileExtension( url.full() );
00124     }
00125     
00126     //override
00127     unsigned int getMaxDataLevel() const 
00128     {
00129         return _maxDataLevel;
00130     }
00131 
00132     osg::Image*
00133     createImage( const TileKey& key, ProgressCallback* progress )
00134     {
00135         if ( !_image.valid() || key.getLevelOfDetail() > getMaxDataLevel() )
00136             return NULL;
00137 
00138         GeoImage cropped = _image.crop( key.getExtent(), true, getPixelsPerTile(), getPixelsPerTile() );
00139         return cropped.valid() ? cropped.takeImage() : 0L;
00140     }
00141 
00142     std::string
00143     getExtension() const 
00144     {
00145         return _extension;
00146     }
00147 
00148 private:
00149     std::string _extension;
00150     int _maxDataLevel;
00151     GeoImage _image;
00152     const OSGOptions _options;
00153 };
00154 
00155 
00163 class OSGTileSourceFactory : public TileSourceDriver
00164 {
00165 public:
00166     OSGTileSourceFactory()
00167     {
00168         supportsExtension( "osgearth_osg", "OSG image driver for osgEarth" );
00169     }
00170 
00171     virtual const char* className()
00172     {
00173         return "OSG Image Driver";
00174     }
00175 
00176     virtual ReadResult readObject(const std::string& file_name, const Options* options) const
00177     {
00178         if ( !acceptsExtension(osgDB::getLowerCaseFileExtension( file_name )))
00179             return ReadResult::FILE_NOT_HANDLED;
00180 
00181         return new OSGTileSource( getTileSourceOptions(options) );
00182     }
00183 };
00184 
00185 REGISTER_OSGPLUGIN(osgearth_osg, OSGTileSourceFactory)
00186 
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